If you know to speak and read Japanese, you should be glad that after over a decade Kingdom Hearts III will be released in Japan on January 25, 2019. They get dibs on everything. The Western counterpart of Kingdom Hearts III will be released on January 29.
Not much is known about Kingdom Hearts III, except that it will conclude the current story arc - leaving doors open for future cash cows. Toy Story will be in it, as well as Monsters Inc. We can probably guess long-overdue titles like Finding Nemo and Incredibles. Others, despite being owned by Disney, such as Star Wars and Marvel characters are most likely a no-show. Maybe in the far future. Then there will be some old worlds to visit again - like Mt. Olympus from Hercules and Halloween Town from A Nightmare Before Christmas. Let's all hope we don't get another awful music level from Little Mermaid. Recent Final Fantasy characters like Tidus, Lightning, and Noctis, will probably make their own appearances as well. Sephiroth as another secret uber boss again, maybe? Third time's the charm.
It's funny why would Square Enix drop the bomb despite their own E3 conference is only a few days away. Most likely this is because of the limited time to present all the other announcements. We are expecting a lot from Square Enix, after all, which includes the Avengers game, maybe a Guardians of the Galaxy, Final Fantasy VII Remake, a bit more about Kingdom Hearts III, and other surprises like Final Fantasy XVI? No? Too early for that.
In any case, do check out Utada Hikaru's song for Kingdom Hearts III,"Don't Think Twice."